1. Field of the Invention
The present invention relates to controlling a point-of-load (“POL”) regulator, or more particularly, to a system and method of utilizing a POL control unit to program and/or monitor a POL regulator.
2. Description of Related Art
Point-of-load (“POL”) regulators, which are also referred to as voltage regulators or DC/DC converters, are commonly used in conjunction with electronic circuits. This is because the voltage/current requirements of electronic circuits typically differ from the voltage that is readily available or the current that can practically be delivered. For example, some electronic devices only include a single voltage input (e.g., 12 v), but require different voltages for circuits contained within (e.g., 3 v, 5 v, 9 v, etc.). A common solution is to design multiple POL regulators within the device for converting the single input voltage into multiple voltage levels.
Similarly, some electronic devices include circuits that require low voltage (e.g., 1 v), high current (e.g., 100 A) power supplies. This is problematic in that it is impractical to deliver high current at low voltage levels over a relatively long distance and still meet desired regulation performances. A common solution is to use a high voltage, low current power supply and design a POL regulator near the internal circuit. This allows low current to travel throughout the device, and provides a low voltage, high current power supply (i.e., using the POL regulator) near the internal circuit.
Traditionally, POL regulators operate in conjunction with at least one power supply controller. The controller activates and partially programs the POL regulator by providing data directly to the POL regulator, and monitors the POL regulator by measuring data external to the POL regulator. Specifically, the controller provides the POL regulator with output-voltage-set-point data and enable data. The POL regulator, which has been manually pre-programmed (e.g., hard wired, etc.) to produce a particular current level, produces an output having a voltage level in accordance with the output-voltage-set-point data. The output of the POL regulator passes through a current sense resistor and a transistor switch connected in series with a load circuit. The controller, through its connections to the current sense resistor and the output terminal of the POL regulator, is then able to measure the output voltage/current that is being delivered by the POL regulator. If the output voltage or current exceeds a known value, the controller can disable the POL regulator by communicating directly with the POL regulator or disconnecting the load by opening the transistor switch.
The drawback with such a control system is that it adds complexity, expense and size to the control system by requiring the controller to communicate with multiple devices (e.g., a POL regulator and an external circuit) to program and monitor the POL regulator. Such a system also limits the type of programming and monitoring that can be performed. Thus, it would be advantageous to have a system and method of programming and/or monitoring a POL regulator that overcomes these drawbacks.